Sewer Diversion

Sewer Diversion: s.185 – s.104/116 agreements

Call 0207 536 2778

Sewer Diversion Guidance: It is necessary (under Section 185 of the Water Industry Act 1991) that a sewerage undertaker may alter or remove any relevant pipe or other apparatus from above or below a developer’s land or any adjacent land subject to the developer giving notice under this section and subject to the following:

That the alteration/removal is necessary to enable that developer to carry out a proposed improvement of the land in which he has an interest.

That the request by the developer is not unreasonable.

A sewerage undertaker is entitled to recover any expenses reasonably incurred in carrying out the alteration/removal of any relevant pipe or other apparatus.

This section does not refer to the removal of any pipe laid above or below a street.

Prior to any diversion being considered by the Water Authority, we would organise a written application including a location plan and site layout of the development, with details of sewer(s) crossing the site and the preferred route of diversion(s).

On receipt of our application, the Water Authority will determine the means by which the project will be delivered in accordance with Water Authorities Policy either:

As part of a Section 104 agreement constructed by the developer in conjunction with adoptable sewers.

As a Minor Sewer Diversion, constructed by the developer subject to an exchange of letters.

As a major sewer diversion, constructed by Water Authority or by the developer under the supervision of Water Authority and supported by a legal agreement

Our input in these discussions at an early stage are vital as decisions at this stage dictate if the client can retain control of the works which would impact on construction time-scales and cost implications.

Pipe Jacking method

In a situation where the sewerage pipes have to be laid in deeper ground (3 to 7 meters), the pipe jacking method will be adopted. This method not only minimises the digging of the trench to lay the new pipes but also alleviates disruption to the public.

sewerdiversion.jpg1. To form the pipe jacking or pipe receiving station, a temporary shaft will be set up at the proposed new manhole location.

2. The soil in the temporary shaft is excavated

3. The pipe jacking machine is then set up at the base of the shaft. Upon confirmation of the alignment, the roller cutter at the face of the cutting head machine cuts the soil in front of it.

4. The excavated soil is then fed to the crusher through a pipe and further crushed to smaller pieces, after which it is transported up to the ground surface in a fluid form using a slurry pump.

5. The excavated soil in slurry form is treated by passing it through a number of screens.

6. The dry spoil is then removed from site, so as to keep the works area clean.

7. The new pipe is lowered in sections behind the cutting head machine and gradually pushed behind the cutting head machine into the area excavated. The excavation and pipe installation cycle continues until the cutting head machine reaches the receiving station with the new pipeline laid behind it.

8. A new manhole structure is then constructed in the receiving shaft.

9. Once the manhole construction is completed, the temporary shaft is backfilled and surrounding area reinstated.

10. Finally the manhole is cleaned and inspected by the relevant agency for handing over and commissioning of the new line.

We will supply:

The location of the sewer to be diverted.

A drawing showing the location of the site and details of the proposed sewer diversion.

Details of all properties connected to the sewer and details of any third party land owners.

Statutory undertaker’s information.


Sewer Diversion: s.185 – s.104/116 agreements

Call 0207 536 2778

Divert Abandon Sewer